Former Ottawa County Sheriff Robert Bratton traded in a 40-year career in law enforcement for a felony conviction Wednesday.

Bratton, 60, of Genoa pleaded guilty before U.S. District Court Judge Jack Zouhary to one count of theft concerning programs receiving federal funds. He admitted improperly spending more than $5,000 from his office’s Furtherance of Justice Fund in 2010 while he was still sheriff.

While the charge carries a possible sentence of up to 10 years in prison, Gene Crawford, an assistant federal prosecutor, told the court that Bratton would likely fall into a sentencing range of zero to six months in prison, in part because of his lack of a criminal record and his willingness to take responsibility for the crime. No restitution will be necessary, Mr. Crawford said, because Bratton already repaid the money.

Mr. Crawford said that by law money in the Furtherance of Justice Fund may be used only for official law-enforcement purposes, but Bratton had used money and a credit card linked to the account “to purchase various personal items, including Cedar Point tickets, prescription medicine, and clothing, all of which were not permitted expenses under FOJ fund rules and regulations.”

Asked if the facts laid out by Mr. Crawford were accurate, Bratton said they were.

Dressed in a business suit, Bratton remained composed throughout the 45-minute hearing, becoming emotional only when Judge Zouhary pressed him to talk about his employment history.

Bratton, who in the past also worked for Sylvania Township and Northwood police, spent about 20 years with the Ottawa County Sheriff’s Office. He was elected sheriff in 2004 and held that position until September, 2011, when he resigned to become Genoa’s police chief.

The improper spending was revealed in 2012 by Ohio Auditor David Yost’s office during a special audit. Bratton, who at the time attributed much of the problems to messy record-keeping, repaid the money and repaid the county for the special audit. The Ottawa County Prosecutor’s Office chose not to pursue criminal charges against him.

Noting his “long and honorable career in public service,” Judge Zouhary asked Bratton to explain how this had happened.

Bratton said he had made mistakes — buying gift cards for underprivileged students at local schools without keeping a record of them, for example. He said that during their examination of the fund, auditors found several purchases for which he had no receipts and others that were deemed personal expenses.

While all the money has been repaid, Bratton’s attorney, Rick Kerger, said afterward his client chose to plead guilty even though it meant the end of his career.

“Bob Bratton respects the law,” Mr. Kerger said. “He dedicated his life to it, and when he found he had violated it, he stepped up to take his medicine. While I felt he had a case we could win at trial, Bob simply wanted to deal with the issue head-on and get it behind him.”